Century Air Handler HWCGxxT0A Operating instructions

Brand: Century

Model: Air Handler HWCGxxT0A

Category: Heat pumps

Type: Operating instructions

INSTALLATION GUIDE

HWCGxxT0A Series - Multi-Position

Air Handler (Hydronic Heat)

1. Safety Instruction

WARNING

Potential safety hazards are alerted using the following symbols. The symbol is used in conjunction with terms

that indicate the intensity of the hazard.

This symbol indicates a potentially hazardous situation, which if not avoided,

could result in serious injury, property damage, product damage or death.

This symbol indicates a potentially hazardous situation, which if not avoided,

may result in moderate injury or property damage.

CAUTION

2. Ensure These Steps are Completed to Reduce

Chances of a Frozen Hydronic Coil

• Ensure the air handler motor and control board are receiving

proper power input per the wiring diagram.

• Ensure the hydronic coil has access to a constant water supply as

loss of water movement can lead to a frozen coil.

• Prime the water circulator pump using the purge valve per the

“Start-Up” section of this installation guide.

• Run the pump for ve minutes after priming to ensure no air is in

the system.

• If any interruption to the water supply occurs, prime the water

circulator pump again.

• Insulate the water piping in unconditioned spaces or within

structures that may be unoccupied during freezing conditions.

• If the air handler does not have an internal pump and/or relies on

an external boiler system for hot water, the installer may need to

rewire the system to ensure that it maintains access to a constant

water supply.

Only factory authorized kits and acces-

sories should be used when installing or

modifying this unit unless it is so noted in

these instructions. Some localities may require a licensed

installer/service personnel.

CAUTION

Certied technicians or those individuals

meeting the requirements specied by

NATE may use this information. Property

and product damage or personal injury hazard may occur

without such background.

WARNING

All power sources should be disconnect-

ed prior to servicing. Failure to do so may

cause personal injury or property dam-

age.

WARNING

Product designed and manufactured to

permit installation in accordance with lo-

cal and national building codes. It is the

installer’s responsibility to ensure that product is installed

in strict compliance with national and local codes. Manufac-

turer takes no responsibility for damage (personal, product

or property) caused due to installations violating regula-

tions. In absence of local/state codes, refer to National Elec-

tric Code: NFPA 90A & 90B Uniform Mechanical Code.

WARNING

When this unit is installed in an enclosed

area, such as a garage or utility room with

any Carbon Monoxide producing devices

(i.e. automobile, space heater, water heater etc.) ensure that

the enclosed area is properly ventilated.

WARNING

The unit is designed for operation with

ply. HCI will not be responsible for

damages caused due to modification of the unit to

operate with alternative power sources.

WARNING

108/120V

, single phase, 60 Hz power sup-

Unit is not approved for outdoor installa-

tions.

WARNING

4. Installation Preparation

4A. Clearances

4B. Installation Options

4C. Condensate Drain Preparation

4D. Condensate Drain

4E. Ductwork

Read all the instructions in this guideline carefully while paying spe-

cial attention to the WARNING and CAUTION alerts. If any of the

instructions are unclear; clarify with certied technicians. Gather all

the tools needed for successful installation of the unit prior to begin-

ning the installation.

This unit is designed for zero clearance installation on three sides

and adequate clearance to provide access for service in the front.

A minimum of 2.5 – 3.5 feet clearance is recommended on the front

end (Fig 4A-1).

If the unit is to be installed in garages, warehouses or other areas

where they may be subjected to physical damage, adequate protec-

tive barriers must be installed. Unit MUST be installed 18” away from

source of ignition.

If the unit is located in high humidity areas like attics or uncondi-

tioned garage; the air handler casing might experience nuisance

sweating. In such installation scenarios, wrapping the casing with a

2” berglass insulation with vapor barrier SHOULD be used.

The drain lines must be installed with ¼” per foot pitch to provide free

drainage. A condensate trap MUST be installed on the primary drain

line to ensure proper drainage of the condensate. The trap must be

installed in the drain line below the bottom of the drain pan (Fig.

4D-1)

Since coil is upstream of the blower, all drains MUST be

trapped or sealed. Failure to do so will re-

sult in condensate overow from the drain

pan. HCI will NOT be responsible for any

damages resulting from failure to follow these instructions.

CAUTION

Ductwork for air conditioning systems should be installed in accor-

dance with standards of the National Fire Protection Association

Pamphlet No. 90A or 90B, and also be sized in accordance with

National Environmental System Contractors Association Manual K,

whichever is applicable.

On any job, non-ammable exible collars should be used for the

return air and discharge connections to prevent transmission of vi-

bration. Although these units have been specially designed for quiet

vibration-free operation, air ducts can act as soundboards, and if

poorly installed, amplify the slightest vibration to the annoyance level.

All main supply and return air drops should be properly size as deter-

mined by the designer of the duct system and should not necessarily

be the size of the duct ange openings of the unit.

The drain pan has primary (white) and secondary (red) drain connec-

tions. If a secondary drain line is required, it should be run separately

from the primary and should terminate in a highly visible location.

Condensate disposal through the secondary drain line indicates that

the primary drain line is plugged and needs cleaning. If a second-

ary drain line will not be provided, plug the secondary drain. Drain

plugs are NOT to be reused without plumbers tape or putty. Drain

line connection should be nger tightened, then turned no more than

one complete turn as needed to ensure a rm connection. DO NOT

overtighten connection or damage may occur.

Fig 4A-1. Minimum Clearance for Air Handler

Fig 4D-1. Condensate Drain Trap

3. Inspection

ü On receiving the product, visually inspect it for any major shipping

related damages. Shipping damages are the carrier’s responsibility.

Inspect the product labels to verify the model number and options

are in accordance with your order. Manufacturer will not accept dam-

age claims for incorrectly shipped product.

Drain lines from the auxiliary drain pan

should NOT be connected to the primary

drain line of the coil.

CAUTION

ü An auxiliary drain pan must be provided by the installer and placed

under the entire unit with a separate drain line that is properly sloped

and terminated in an area visible to the home owner. The auxiliary

pans provide extra protection to the area under the unit should the

primary and secondary drain plug up and overflow. As expressed

in our product warranty; HCI WILL NOT BE BILLED FOR ANY

STRUCTURAL DAMAGES CAUSE BY FAILURE TO FOLLOW

If the drain pan is constructed of nylon

or plastic; use Teon tape to connect the

drain lines to the threads in the drain pan.

DO NOT USE SOLVENT BASED PIPE DOPE. THIS WILL RE-

DUCE THE LIFE OF THE PAN.

CAUTION

THIS INSTALLATION REQUIREMENT. The drains from the auxil-

iary drain pan must be installed according to the local building codes.

5. Installation

Ensure that the unit is adequately sized.

The tonnage of the outdoor unit should

never exceed the tonnage of this unit.

CAUTION

Only lead free solder should be used to

connect water (hydronic) coil to the hot

water source.

CAUTION

The coil was manufactured with a dry ni-

trogen pre-charge. Release the pressure

through the Schrader valve test port prior

to installation. If holding pressure is not present, return coil

to distributor for exchange.

WARNING

Prior to connecting the water (hydronic)

coil, make sure that the hot water supply

is turned off. Water from the heater could

be extremely hot and might result in burns and other person-

al injury along with equipment damage. Ensure that proper

safety gear is being used prior to making connections.

WARNING

Some HCI coils may include a Schrader

valve on the suction manifold. Ensure that

the Schrader valve and valve core (where

present) are protected from heat during brazing and instal-

lation to prevent leakage. Use a core removal tool to tempo-

rarily remove the core when brazing. Replace the core once

brazing is completed.

CAUTION

5. Air Handler Orientation

This unit can be installed in vertical or right horizontal position with-

out modications. In case of a counterow application, the horizontal

drain pan MUST be removed. Fig. 6-1 shows the various orientations

this air handler can be installed in.

When the unit is used in a horizontal orienta-

tion, an auxiliary drain pan MUST be provided

by the installer and placed under the entire

unit with a separate drain line that is properly sloped and ter-

minated in an area visible to the home owner. The auxiliary pan

provides extra protection to the area under the unit should the

primary and secondary drains become plugged and overow. As

expressed in our product warranty, failure to follow this instal-

lation requirement will void the product warranty. The drain

from the auxiliary drain pan must be installed according to the

local building codes.

CAUTION

Fig 6-1

1. With Air Handler in vertical position remove all access panels.

2. Remove horizontal drain pan from

right hand side of coil.

6A. Horizontal Left-hand Installation

4. “P” traps must be installed on pri-

mary and secondary drains of the

horizontal drain pan.

3. Relocate the removed horizontal

drain pan to the left side of the coil.

ü Clean coil ns with degreasing agent or mild detergent and rinse

ns clean prior to installation.

ü The refrigerant line sizes should be selected according to the rec-

ommendations of the outdoor unit manufacturer.

ü Care must be taken to ensure all connection joints are burr-free

and clean. Failure to do so may increase chances of a leak. It is

recommended to use a pipe cutter to remove the spun closed end of

the suction line.

ü To reduce air leakage, rubber gommets may be present where the

lines pass through the coil case. To avoid damage, remove grom-

mets prior to brazing by sliding over the lines. Use a quenching cloth

or allow the lines to cool before reinstalling the grommets.

ü Use of wet rags/quenching cloth is highly recommended to prevent

weld-related damages to the casing and Schrader valve (if present).

When installing a central air return grille in or near the living space,

it is advisable to design the ductwork so that the grille is not in direct

line with the opening in the unit. The use of one or two elbows and

acoustical duct liner will also ensure quieter system operation.

It is recommended that wherever supply and return air sheet metal

duct pass through unconditioned areas, they be insulated to pre-

vent excessive heat loss during heating operation. When applied in

conjunction with summer air conditioning, sheet metal duct routed

through unconditioned areas should be insulated and have an out-

side vapor barrier to prevent formation of condensation.

6B. Counter/Downow Installation

Fig 6A-1 - Air ow direction in Horizontal Left application

5. Reinstall all access panels to the

unit.

A downow kit (DFK) is required for counter/downow air handler

installation

1. Remove the bottom access panel (1), top access panel (2), lter

cover (4), and air lter (5.) Remove the A-coil assembly (6) with side

drain pan (3) as shown in gure below.

2. Rotate the unit 180° as shown in the

gure. Discard existing bottom access

panel (1), top access panel (2) and side

drain pan (3.)

180° Rotation

3. For STYLE 1 downow kit ,rotate the lter rails 180° and re-in-

stalled the lter rails. After fastening lter rails, slide the air lter back

as shown below (A).

For STYLE 2,Fasten the Filter Rails D and E to the wrapper and slide

the air lter back as shown below (B).

A: Style 1

B: Style 2

4. Add Block Off Plate C

on the both side of coil as

shown.

7. Connecting Ducting

1. Secure supply air ducting to the top of the air handler. Canvas connectors are recommended for reducing potential noise transmission.

2. Secure the return air ducting to the air handler cabinet.

8. Metering Devices/Liquid Line Connection

HCI coils are available with two kinds of metering devices a) flowrator or b) TXV. The following instructions are separated into

sections by metering device.

5. Re-install and fasten the coil deck. After installing coil deck prop-

erly, slide the coil assembly back as shown below.

6. Install and fasten the lter cover rst,then the blower and control

access panel B and last will be coil access panel A to the unit as

shown below

The process of re-installing downow application conguration for

Style 1 and Style 2 respectively:

Re-installing Downow Conguration Style-1

Re-installing Downow Conguration Style-2

Note: Photos are for basic illustration purposes only. Actual equip-

ment conguration may differ from that shown.

Use Piston sizes recommended by the

outdoor unit manufacturer whenever pos-

sible. The piston should be sized accord-

ing to the capacity of the outdoor unit.

CAUTION

Fig 8A-1. Flowrator assembly components

Failure to install the proper piston can

lead to poor system performance and

possible compressor damage.

WARNING

I. Installation

I-1. Disassemble owrator body

using two wrenches and un-

screwing with a counterclockwise

motion.

8A. Flowrator Coils

I-4. Braze the stub-out portion to the liquid line and let cool.

I-3. Slide the attachment nut onto

the liquid line stub out.

I-6. Tighten the nut to a torque of approximately 10-30 ft-lbs. Do NOT

overtighten the nut. Overtightening will impede the piston movement

during operation.

I-5. Taking care that the white

Teon seal is still in place inside

the owrater body, rmly seat the

stub and screw the attachment

nut to owrater body.

O-ring

Be aware of the Teon O-ring. Be sure to

replace the O-ring to attain a proper

seal. (The Teon O-ring is located between

the two halves of the owrator)

CAUTION

I-2. Replace the Teon O-ring

(located between the halves).

Discard Schrader if present.

O-ring

During some installations, a piston change may

be required. If so, the installer MUST change the

piston. Use piston sizes recommended by the

outdoor unit manufacturer. If a sizing chart is not

available, use the piston size chart provided be-

low to size the required piston. The size of the

piston is stamped on the piston body (Fig 8A-2).

II. Piston Replacement

Fig 8A-2

Use the chart below when matching coil with an outdoor unit with a

different nominal capacity than the coil.

Note: Photos are for basic illustration purposes only. Actual equip-

ment conguration may differ from that shown.

II-4. Slide the 13/16” nut over

the lineset and separate the two

halves of the owrator.

II-1. Evacuate the system as per manufacturer guidelines and rec-

ommendations

II-2. Turn the 13/16” nut once to release any residual pressure in the

coil.

II-3. After ensuring that the coil

is free of any residual pressure,

disassemble the owrator body

completely using two wrenches.

Take great care not to distort the

feeder tubes. The wrench used

to clasp the nut should be turned

in counter-clockwise direction to

unscrew the nut.

Be aware of the Teon O-ring. Be sure to

replace the O-ring to attain a proper

seal. (The Teon O-ring is located between

the two halves of the owrator)

CAUTION

Pay close attention to the piston orienta-

tion. The pointed end of the piston MUST

go into the distributor body, towards the

coil. Failure to ensure this orientation will cause the piston

to be bypassed during operation which might damage the

outdoor unit.

CAUTION

II-6. Replace the piston with one

of the correct size. Do not force

the new piston into the body.

Make sure the piston moves

freely in body.

II-7. Assemble the two halves correctly and ensure that the white

Teon O-ring is present between the two halves (See I-5). Slide the

13/16” nut onto the distributor body.

II-8. Tighten the nut to a torque of approximately 10-30 ft-lbs. Do NOT

overtighten the nut. Overtightening will impede the piston movement

during operation.

II-9. If present, slide the rubber grommet back to position to prevent

air leakage.

7B. TXV Coils

Ensure that the TXV selected is compat-

ible with the refrigerant used in the out-

door system (R22 or R410A). TXV caps are

painted green for R22 or pink for R410A. In absence of col-

or, the caps will be marked with the compatible refrigerant.

CAUTION

The sensing bulb and TXV body MUST be

protected from overheating during braz-

ing. The sensing bulb and TXV body must

be covered using a quench cloth or wet cloth when brazing.

Pointing the brazing ame away from the valve and sensing

bulb provide partial protection only.

WARNING

Fig 8B-1. Components of a typical TXV assembly

The valves should be sized according to

the capacity of the outdoor unit. Failure to

install the right valve can lead to poor per-

formance and possible compressor damage.

CAUTION

Ensure that the TXV bulb is in direct con-

tact with the suction/vapor line. Gap be-

tween the bulb and tube should be avoid-

ed. Failure to do so will impair the proper functioning of the

TXV valve.

CAUTION

I. TXV Bulb Horizontal Mounting

The orientation and location of the TXV bulb has a major inuence

on the system performance.

II-5. Pull the piston out using a

small wire or pick. Verify the pis-

ton size (size is typically stamped

on the body of the piston - Fig

8A-2). If a different piston size

is required by the outdoor unit

manufacturer, replace the piston

using the small wire provided with

the piston kit.

It is recommended that the TXV bulb be installed parallel to the

ground (on a horizontal plane). The bulb position should be at

2 o’clock or 10 o’clock. Fig. 7B-2 shows the recommended position

for the TXV bulb installation in the horizontal plane.

The TXV sensing bulb SHOULD be mounted on the suction line ap-

proximately 6” from the TXV or coil housing using the metal clamp

provided. In order to obtain a good temperature reading and correct

superheat control, the TXV sensing bulb must conform to ALL of the

following criteria:

1. The sensing bulb MUST be in direct and continuous

contact with the suction line.

2. The sensing bulb should be mounted horizontally on

the suction line.

3. The sensing bulb MUST be mounted at the 2 o’clock or

10 o’clock position on the circumference of the suction line.

4. The sensing bulb MUST be insulated from outside air.

A properly mounted sensing bulb will prevent false readings caused

by liquid refrigerant that may have formed inside the suction/vapor

line. Insulation will protect the sensing bulb from false readings due

to contact with warm air.

Fig 7B-2. Recommended location for horizontal TXV bulb mount

Bulb position at

2 o’clock or

10 o’clock

If the TXV sensing bulb is mounted verti-

cally, the capillary MUST be directed up-

wards. The bulb must be mounted on the

wall opposite to that being directly hit by the refrigerant and

oil leaving the distributor tubes.

CAUTION

II. TXV Bulb Vertical Mounting

Fig 8B-3. Recommended location

for vertical TXV bulb mount

As recommended in Section

8B-I, the TXV sensing bulb

should be mounted in a hori-

zontal plane in relation to the

suction/vapor line. However,

some installation congura-

tions may require that the

sensing bulb be mounted ver-

tically. In this instance, place

the bulb opposite the piping

wall being hit by refrigerant

and oil leaving the distributor

tubes, and with capillary tubes

directed upwards as shown in

Fig. 8B-3.

III-3. Replace the Teon O-ring

seal in place (located between

the halves).

O-ring

III-2. Remove the existing ow-

rator piston using a small wire

or pick.

Note: Photos are for basic illustration purposes only. Actual equip-

ment conguration may differ from that shown.

III. Field-Installed TXV Retrot

When installing an expansion valve, it is not necessary to slide the

coil out of the housing.

III-1. Disassemble the owrator

body using two wrenches. Un-

screw the body with a counter-

clockwise motion.

III-4. Inspect the TXV box to conrm that the valve is compatible

with the refrigerant in the system.

Male

(Inlet)

Female

(Outlet)

III-5. Remove the valve from

the box and note the loca-

tion of the inlet side (threaded

male port) and the outlet side

(female swivel nut port).

III-8. Braze the stub-out portion to the liquid line and let cool.

III-7. Slide attachment the nut onto the liquid line stub out

(See 8A, I-3)

Do not attempt to touch brazed joints

while hot. Severe burns may result.

WARNING

O-ring

III-6. After ensuring that the

Teon O-ring seal is still in place

inside the owrator body, screw

the female swivel nut onto the

owrator body.

O-ring

III-9. Remove the additional Tef-

lon O-ring seal from the box and

place on the shoulder just inside

the TXV inlet port. Screw the nut

attached to the stub-out portion of

the owrator body onto the inlet

port of the TXV.

A. Remove the valve stem from

the Schrader port mounted on the

suction line.

III-10. Tighten all connections taking care to use proper back up.

III-11. Remove the valve identification sticker from the valve and place it

adjacent to the HCI model number on unit name plate.

III-12a. Some HCI coils come with a Schrader valve on the suc-tion line.

If a Schrader port is present:

B. Screw are nut on TXV equal-

ization tube on to the Schrader

valve stem.

III-12b. In some cases, a suction line schrader port may not be

present. If a Schrader port is NOT present:

When handling or manipulating the equal-

izer tube, take great care not to kink or

make extreme bends in the tubing.

CAUTION

A. Install a eld-supplied braze-on schrader

valve like that shown on the suction line near the

intended sensing bulb mounting location. Fol-

low valve manufacturer instructions and recom-

mendations for installation.

B. Attach equalizer tube to valve as described in

section III-12a above.

III-13. Mount the sensing bulb as described in section 8B-I or 8B-II.

9. Connecting Refrigerant Lines

11. Electrical Installation

1. Release nitrogen hold-

ing charge by depressing the

Shrader Valve at the liquid line

connection on the air handler.

If no gas releases from the air

handler, contact distributor re-

garding potential leak.

2. Cut off Shrader Valve tting at

the liquid line connection. Use a

tubing cutter for this step. Clean

the burr from the cut tubing to

reduce the chance of future

leaks. Connect the liquid line to

the tubing at the indoor unit.

3. Use a tubing cutter to remove

the spun end from the suction

line connection at the air han-

dler. Clean the burr from the cut

tubing to reduce the chance of

future leaks.

4. To avoid heat damage to grommets where present, remove these

prior to brazing by sliding them over the refrigerant lines and out of

the way.

5. Check to determine if the

evaporator coil has a Shrader

tting on the suction manifold.

If yes, remove the valve core

to prevent heat damage during

brazing. Replace the valve core

once the piping has cooled.

6. If the air handler has a TXV metering device, remove the sensing

bulb from the suction line prior to brazing to prevent heat damage

from occurring. Replace the sensing bulb once the piping has cooled.

7. Flow nitrogen through the piping when brazing.

8. Braze both refrigerant line connections using proper brazing pro-

cedures.

9. When all line connections are brazed, perform a proper system

evacuation procedure per the outdoor unit manufacturer instructions.

10. Seal the penetration openings where the lineset piping enters the

air handler cabinet.

1. Following outdoor unit manufacturer instructions and recommen-

dations, charge the system with dry nitrogen to a maximum pressure

of 150 PSIG.

3. If any leaks are discovered, relieve system pressure and repair

leaks. Repeat steps 1-3.

4. With no leaks or weak connections present, evacuate the system

and charge as per the outdoor unit manufacturer instructions and

specications.

10. Leak Check

2. Check all brazed and screw-

on line connections by applying a

soap solution to the joint. A leak

will produce bubbles in the soap

solution.

These units are designed for a single phase 120 volts, 60 Hz power

supply. Wire selection and wiring must be in accordance with the Na-

tional Electric Code and/or local codes. Unit terminals are designed

to accommodate copper or aluminum wiring. If aluminum wiring is

used; please observe special precautions relative to sizing, wire con-

nections and corrosion protection.

Fig.11-1 shows the typical electrical connections required for A/C

only and heat pump applications.

Fig 11-1.

Line voltage wiring should be

routed through the access holes

at the top of the air handler.

Proper electrical conduit con-

nection ttings should be used.

Connect the power wiring to the

line side connections on the air

handler. The electrical ground

wire should be connected to the

grounding lug. Ensure both the

eld supplied ground wire and air

handler GREEN ground wire are

both secured to the grounding

lug of the air handler (Fig 11-2).

The aquastat (AQ) jumper must be in the

OFF position at all times, except for when

an aquastat is used. If the jumper is moved

to the ON position without installing an aquastat, the blower

will not be energized.

CAUTION

The unit ships with a micro-processor based board which controls

the electrical functioning of the unit. An inspection of the controls is

recommended prior to startup.

Fig.11-B2 provides a schematic of the control board present in the

unit. The unit ships from the factory with the aquastat jumper in the

OFF position (right two pins) and the heating selector in the HW

position (right two pins). If an aquastat is used in the application; the

jumper should be changed to the ON position (left two pins).

Note: Terminals T and N located on the top right side of the board are

not intended for eld use and should be left disconnected.

Fig 11A-2.

Fig 11-2.

Fig 11B-2.

11B. Jumper Placement

11C. Pump/Valve/Boiler Wiring

Operating CFM based upon each speed tap number is shown on

the electrical wiring diagram of the unit. Final air volume adjustments

should be made by referencing total external static pressure (Table

11A-1).

Table 11A-1.

11A. Single Stage Cooling

On units shipped from the factory with a pump installed (Fig 11C-3),

the pump will be energized on a call for heat.

Fig 11C-3.

During cooling mode operation, indoor blower wire “G” will energize

a time delay relay located on the control board inside the air han-

dler. After a short time delay period, the time delay relay will apply

120VAC to the motor via the “MTR“ terminal. (See Schematic Fig

22-1.) Fan time delay periods are 30 seconds ON delay and 120

seconds OFF delay.

The Y wire from the thermostat is not connected at the air handler.

This wire goes directly to the outdoor unit 24 volt wiring to turn on

the outdoor condensing unit when a call for cooling takes place. The

24 volt common for the outdoor unit circuitry is connected at the air

handler brown wire. (See Fig11-1.)

The hydronic heater low voltage wiring terminal “W” is wired directly

from the thermostat to the air handler. The indoor blower, on a call for

heat, will ON delay for a period of 5 seconds. When the call for heat

has been satised, the indoor blower will have an OFF delay time

period of 60 seconds.

On units that were shipped without factory installed pumps, two

black wires should be connected to the terminals marked “BOILER”

T T (see Fig 11B-2). In applications where a boiler provides the hot

water supply, these wires should be connected to the boiler control

wiring. Terminals “BOILER” T T are normally open dry contacts.

23/24

35/36

47/48/60

The freeze protection sensor is connected to the “FP” and “R“ ter-

minals. This sensor is normally open and will close when the sensor

detects a temperature of less than 40ºF. The pump will operate and

stay ON for a minimum of 30 seconds.

The board has a built-in timer which circulates hot water 6 times a

day for 60 seconds to prevent the hydronic coil from freezing.

12. Condensate Drain

1. Select desired condensate drain openings according to air han-

dler orientation. Both Primary and Secondary outlets can be used.

2. Pipe condensate system using proper PVC ttings.

3. Ensure a minimum 2” trap

is installed in the condensate

drain. Locate the trap near to

the connection opening on the

air handler. See illustration.

Air volume needs to be set to the level recommended by the outdoor

unit equipment manufacturer. Most systems will require around 400

CFM of indoor air for every 1 ton of system cooling capacity. The air

volume must be set prior to attempting system charge.

This air handler uses a PSC type motor. The speed of this motor

is set by placing the appropriate winding lead wire on the “MTR”

terminal of the control board. Unused motor winding leads are to

be placed on the “BLANK” terminals on the control board. The air

volume level produced by the air handlers at varying external static

pressure levels is shown in Table 13-1.

Use a Magnehelic Gauge with a 1” scale and two static pressure

tips to measure the static pressure during the air volume adjustment

procedure (Fig. 13-1). The high port static pressure tip should be

placed in the supply duct near the outlet of the air handler. The low

port static pressure tip should be placed in the return air duct near

the entrance to the air handler. The factory provided air lter should

be in place inside of the air handler.

13. Air Volume Adjustment

Table 13-1.

Fig. 13-1

1. Select a speed tap from the CFM table and connect appropriate

motor lead wire to the “MTR“ terminal on the control board.

2. Call for fan only operation at the thermostat.

3. Read the external static pressure level on the Magnehelic gauge.

4. Make speed tap selection change to get the air volume as close

as possible to the required level.

11D. Freeze Protection Sensor Wiring

In applications where a valve or pump is used to regulate the hot

water supply, the two black wires located on the “BOILER” T T ter-

minals should be removed and placed on the two terminals marked

“VALVE”. These wires should be connected to a 24V valve or pump

relay according to local requirements and instructions of the valve or

relay manufacturer.

On a call for heat, 24V will be sent to the eld-installed valve or pump

relay, the valve will open or pump relay will close contacts allowing

the pump to run. Water will circulate through the water (hydronic) coil

for 60 seconds prior to energizing the blower. After the thermostat is

satised, the blower will continue to stay energized for a minimum of

30 seconds. The additional blower run time helps maximize heating

efciency.

5. If the static pressure is above .5” wc, excessive turbu-

lence or duct friction needs to be reduced. (Obstructions in

the duct system can also cause excessive static pressure.)

6. When proper air volume is established, move on to the charging

procedure.

1. Bring airow up to the maximum CFM possible according to Table

12-1.

2. Evacuate refrigeration system to micron level required by outdoor

unit manufacturer.

3. Release system charge from outdoor unit and call for cooling.

4. Use outdoor unit equipment manufacturer specific charging charts

if available and make proper charge adjustment based upon outdoor

unit instructions.

5. If outdoor unit instructions and charts are not available, use HCI

provided charts. Make certain indoor air temperature is near comfort

level setpoint of 75°F prior to establishing superheat and subcooling

levels.

14. System Charging

An improperly charged system may cause

degradation in system performance and

damage the compressor. After installation

of the coil, refer to the outdoor unit manufacturer for charging

techniques and amount of charge. If outdoor unit manufacturers

charging instructions are unavailable, then refer to instructions

below to charge the system.

CAUTION

23/24

35/36

47/48/60

16. Start-Up

The hot water (hydronic) coil and all wa-

ter lines MUST be purged of air prior to

starting the pump. Failure to do so could

result in pump damage. HCI will not be

responsible for any property or personnel damage caused

by failure to fol-low this instruction.

WARNING

After all connections are made, start-up and checkout must be per-

formed before proper evaluation of the entire system can be made.

Make sure that heat anticipator is properly set as noted on thermo-

stat instructions. Load requirements can vary in each residence and

it may be necessary for the installer or homeowner to make slight ad-

justments to the heat anticipator setting for longer or shorter cycles.

It is recommended to change the setting no more than plus or minus

0.05 amps at a time. Greater changes can cause the unit to rapid

cycle or remain on excessively.

15. Adjustment Of Heat Anticipator

Hot water owing to the coil should be in

the range of 120º - 180º F. Water at these

temperatures can cause rst-degree

burns. Use of proper safety gear while installing or servicing

the equipment is strongly recommended as is installation

of a water-tempering valve (for water temperatures of above

140ºF) to supply lower temperature water to xtures in the

house. N170L series or equivalent should be used.

WARNING

Connect the hydronic coil to the water heater system as shown in Fig

16-1 and 16-2. Use exible piping and insulate all pipes. Plumbing

must be in compliance with state or local codes (Code CMR248 in

Massachusetts). The units for hydronic heat have different top and

heater box congurations. This conguration is not suitable for elec-

tric heat. DO NOT try to install hydronic heater in a unit not equipped

for it. Verify connections: hot water to “in” and cold water to “out”. 7/8”

OD stubs are provided for plumbing connections. Bleed the air ow

system through the bleeder port or optional valve.

Fig 16-1.

Fig 16-2.

Purging The System

1. Open air vent and allow water heater to ll with water. Close air

vent when water heater is full and all air has been purged.

2. Ignite water heater. Set thermostat on water heater to 140 de-

grees.

3. Close the valve on the hot water supply from the water heater (“A”)

and open the valve on the cold water return to the water heater (“B”).

Then open the air vent in the fan coil. Use bucket or hose to discard

water during purging process at air bleed valve. Purge air completely

from line.

4. Once air is purged, close return valve (“B”) and open supply valve

(“A”). Purge the coil and lines of air completely.

5. After air is purged from the system and lled with water, open the

return valve (“B”). Then close the air vent in the fan coil.

6. Apply power to the fan coil and set the room thermostat on heat.

Raise the temperature setting to activate the circulating pump

7. Check the pump to ensure proper operation. The water inlet of the

unit should be hot if the water temperature in the water heater has

reached the set point. If water is not being circulated through the coil

but the pump is running, then open the air bleed valve in the unit and

purge any air left in the system.

Add refrigerant until the superheat measured at the outdoor unit suc-

tion/vapor line matches the superheat from the chart below.

15A . Flowrator Coils

Add refrigerant until the subcooling measured at the outdoor unit

liquid line matches the subcooling recommendation of the outdoor

manufacturer. If chart is unavailable charge the unit to a subcooling

value of 8ºF +/- 1ºF.

Table 15B-1.

15B . Expansion Valve Coils

Outdoor

Temp

Superheat

°F D.B. Min Nom Max

65 30 35 40

70 26 30 34

75 21 25 29

80 17 20 23

85 12 15 18

90 8 10 12

4 5 7

100

Installer MUST open water lines and run

system to a.) ensure pump is primed and

waterow is constant and b.) ensure there

are no leaks in the coils, connections, and/or water piping.

Failure to do so could result in water leaks and property dam-

age. HCI will not be responsible for any damage caused

by failure to follow this instruction.

WARNING

Turn on power supply. Set thermostat fan switch to on. Set the cool-

ing indicator to maximum, heating to minimum. System switch may

be on heat or cool. Check slope gauge measurement against appro-

priate air ow chart. Make damper, register and motor speed adjust-

ments to obtain required airow.

Set thermostat fan switch to auto, system to heat and thermostat

heating indicator to maximum heat. Blower should start and all heat

be energized.

Check air ow using temperature rise method.

17. Checking Air Flow/Temperature Rise Method

Table 16-1. - CFM Delivered at Various External Statics

CFM

OUTPUT BTUH

TEMP RISE

•

()

..108

Note: BTUH output should be computed by 500 x Gallons Per Min-

utes x System Temperature Change = BTUH OUTPUT.

8. Adjust the water heater thermostat so that the water temperature

entering the hot water coils is 120 – 180ºF depending on the amount

of heat required by the structure. This is done with the unit energized

and operating long enough for all temperatures to stabilize.

After all connections are made, start-up and check-out must be per-

formed before proper evaluation of the entire system can be made.

Make sure that heat anticipator is properly set as noted on thermo-

stat instructions.

Load requirements can vary in each residence and it may be neces-

sary for the installer or homeowner to make slight adjustments to the

heat anticipator setting for longer or shorter cycles. It is recommend-

ed to change the setting no more than plus or minus 0.05 amps at

a time. Greater changes can cause the unit to rapid cycle or remain

on excessively. To properly check the unit’s operation, the installer

should have an electrical current measuring device (0-10 amp Am-

probe, Fluke), air pressure measuring device (0-1.0 in slope gauge),

and a temperature-measuring device (0-200ºF thermometer).

Install the Amprobe to measure blower current, the slope gauge to

measure static air pressure at the units and the temperature device

to measure unit supply and return air temperature. Before taking

measurements, be sure that all registers, grilles and dampers are

open or are set to their proper positions. Be sure that clean lters are

in place. Temperature measuring device must be installed to obtain

average temperature at both inlet and outlet. For outlet, measure

temperature of each main trunk at a location far enough away to

avoid heater radiation and read the average temperatures. Table

16-1 below shows the CFM that should be achieved at various exter-

nal static pressures.

Below are brief descriptions of the key components of the unit and in-

stallation. This manual only provides general idea of the components

and recommended practices. The installer should use best judge-

ment to ensure safe installation and operation of the unit.

1. Room Thermostat- This is the device that controls that operation

of your heating and/or cooling unit. It senses the indoor temperature

and signals the equipment to start or stop maintaining the tempera-

ture you have selected for your comfort. The room thermostat should

be in a central, draft free inside wall location for best operation. Do

not place any heat producing apparatus such as lights, radio, etc.,

near the thermostat as this will cause erratic operation of the comfort

system. The thermostat can accumulate dust or lint which can affect

its accuracy. It should be cleaned annually.

2. Air Filter(s) - All central air moving comfort systems must include

air lter(s). These lters will be located either in the equipment or in

the return air duct system upstream of the equipment. The lter(s)

removes dust and debris from the air thus helping to keep your air-

conditioned space clean. More important, the lter keeps dust and

debris from collecting on the heat transfer surfaces thus maintaining

optimum equipment efciency and performance. Inspect and clean

or replace lters every month. This routine maintenance procedure

will pay big dividends in reduced operating cost and reduced service

expense. Never operate comfort equipment without lter(s).

3. Fuses and/or Circuit Breakers- This comfort equipment should be

connected to the building electric service in accordance with local

and National Electric codes. This electrical connection will include

over-current protection in the form of circuit breakers. Have your

contractor identify the circuits and the location of over-current protec-

tion so that you will be in a position to make inspections or replace-

ments in the event the equipment fails to operate.

18. Operation and Maintenance

5. Periodic Checkup and Service- This product is designed to pro-

vide many years of dependable, trouble-free comfort when properly

maintained. Proper maintenance will consist of annual check-ups

and cleaning of the internal electrical and heat transfer components

by a qualied service technician. Failure to provide periodic checkup

and cleaning can result in excessive operating cost and/or equip-

ment malfunction.

6. Lubrication- Direct drive blower motors are equipped with perma-

nently lubricated bearings and do not require further lubrication.

7. Air lter replacement: An air lter can restrict the airow of air to

the fan coil if it is not cleaned or replaced periodically. When replac-

ing the air lter, always replace with the same type and size as origi-

nally furnished with the unit.

4. a) Do not store combustible materials

or use gasoline or other ammable liquids

or vapors in the vicinity of this appliance.

b) Do not operate the comfort equipment with panels re-

moved.

c) Have your contractor point out and identify the various

cut-off devices, switches, etc., that serve your comfort

equipment. There is a main switch that will cut off energy to

your heating system. Know where they are so that you may

cut off the ow of energy in the event of overheating.

WARNING

23/24

35/36

47/48/60

1. Equipment Sizing Select an air handler with a heating output

that exceeds the space heating loss of the structure and that has a

cooling coil sized to match the outdoor condensing unit. Note: The

heating output of the air handler or hot water coil will not be greater

than the output of the selected hot water heater. Therefore, if the

water heater is undersized the heating BTUH of the air handler will

be LESS than its rated output.

2. Water Heater Selection

The following sizing information should only be used as a basic

guide to adequate water heater sizing because of variations in each

family’s domestic hot water requirements. For additional assistance

in water heater sizing contact a professional engineer. Proper water

heater sizing should consider both the gallon capacity AND the BTU

input of the water heater.

a. To determine water heater GALLON CAPACITY: A minimum

40-gallon high recovery and/or high efciency gas or oil-red

water heater is recommended. The following volume-sizing

guide is satisfactory in most areas of the country (Table 19-1).

19.

HWCGxxT0A Hydronic Related General Information

b. To determine water heater BTU INPUT (assumes a water

heater recovery efciency of 76%): For mild climates: BTU

INPUT=structure’s heat loss x 1.51. For colder climates: BTU

INPUT=structure’s heat loss x 1.58.

3. Pump Replacement

a. Disconnect electrical power to the unit before servicing.

b. Remove access door to reveal pump. Close supply valve (“A”)

and return valve (“B”). Open the air bleed valve to de-pressur-

ize the system and drain water.

c. Remove the metal pump housing by loosening the four screws

on the pump. DO NOT UN-SOLDER PUMP.

d. Replace the new pump housing assembly and reconnect com-

ponents to the pump. Before assembling, make sure that the

runner on the o-ring is in place on the pump housing.

e. Purge the system of the air as described earlier and re-connect

the electrical power.

Table 19-1.

4. Little or no heat from water coil.

a. Purge the system.

b. The inlet connections may be reversed at the fan coil.

c. Water heater thermostat is not set at proper temp.

d. Water heater thermostat is not calibrated.

e. Dip tube in the water heater may not be installed correctly or

could be restricted.

f. Look for restrictions in heating system from water heater to fan

coil. Some water heaters are supplier with check valves, re-

move any extra check valves except for the one supplied with

the fan coil.

g. The air handler is undersized for space being heated.

h. Water heater is undersized.

Note: All units installed in Massachusetts are required to be in com-

pliance with CMR 248 Massachusetts State Plumbing Code and/or

Massachusetts Fuel Gas Code.

These codes require the use of an optional pump timer to circulate

the hydronic loop independent of the thermostat.

1. Noisy Pump

System may not be totally purged of air. Purge the system again as

described in the start up section above.

2. T&P valve on water heater weeps This normally occurs when a

backow preventer has been installed in the cold water supply line

to the water heater. An expansion tank may be necessary to correct

this problem. Please contact a qualied plumbing professional for

assistance.

3. Hot water is circulating through the water coil during cooling cycle

The check valve may be stuck open and allowing hot water to circu-

late through the coil.

20. Common Problems and Solutions

21. Final System Checkout

1. Make certain all cabinet openings are properly sealed and any

grommets moved during installation are moved into proper place.

2. With cooling system operating, check for condensate leakage.

3. Perform leak detection inspection of refrigerant circuit and con-

necting piping.

4. Secure all cabinet doors

22. Wiring

diagram for HWCGxxT0A models

HIGH VOLTAGE disconnect all power sources prior to servicing. Failure might lead to safety hazard

Fig 21-1.

23. Massachusetts Applicable Installation Diagram

08/2019

Century Air Handler HWCGxxT0A Operating instructions

Brand: Century

Model: Air Handler HWCGxxT0A

Category: Heat pumps

Type: Operating instructions

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Century Air Handler HWCGxxT0A Operating instructions

Century Air Handler HWCGxxT0A Operating instructions

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